Differences: Porsche 997 1/24?

I´ve found several makers of a 997 Die-cast model in 1:24. Does anybody know if those are exactly the same, distributed under different names?
I would say the Speedy and Bburago model is not like Welly and Schuco.
What do you say?

Welly (http://cgi.ebay.de/PORSCHE-911-CARRERA-S-COUPE-SCHWARZ-1-24-WELLY-074_W0QQitemZ140158073219QQihZ004QQcategoryZ81145Q QrdZ1QQssPageNameZWD1VQQcmdZViewItem)

Schuco (http://cgi.ebay.de/o-o-Schuco-7063-Porsche-911-997-Carrera-S-1-24_W0QQitemZ200128819732QQihZ010QQcategoryZ81145QQ rdZ1QQssPageNameZWD1VQQcmdZViewItem)

Speedy (http://cgi.ebay.de/Porsche-911-Carrea-S_W0QQitemZ7012300943QQihZ017QQcategoryZ223QQrdZ1Q QssPageNameZWD1VQQcmdZViewItem)

Bburago (http://cgi.ebay.de/PORSCHE-911-997-CARRERA-S-COUPE-GEL-1-24-BBURAGO-BURAGO_W0QQitemZ320142026292QQihZ011QQcategoryZ249 5QQcmdZViewItem)

I have a bburago model and while looks nice I'd say it's more toyish car rather than a collectible model. So yeah, I'd agree bburago is likely very different from the other three (which I know nothing about). Interesting thread! :)